1. Field of the Invention
The present invention relates to a vent stack screen for portable toilet holding tanks.
2. Description of the Related Art
A frequent problem with using out door portable johns and toilets is dealing with troublesome flying insects that enter the confined space of the toilet through the holding tanks. Another problem is flying or falling debris accumulating in the holding tanks.
Insect screens in the prior art has taken many forms, for example, published U.S. patent application Ser. No. 2002/0092631 A1 teaches a screen for blocking insects from entry into vent holes provided in brick walls. A, mesh of screen material includes a retainer with resilient fingers for engaging the vent hole to retain the screen over the vent hole.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a vent stack screen for portable toilet holding tanks solving the aforementioned problems is desired.
The present invention provides a vent stack screen for holding tanks in the form of a cap designed to fit over the top of the open air vent stack extending from the holding tank through the roof of a portable toilet. The cap is constructed from a tubular sleeve of plastic material having an inner diameter substantially equal to the outer diameter of the vent stack of a holding tank. The cap includes an inwardly extending annular lip formed at one end. A circular mesh of plastic screen material is secured within the tubular sleeve between the annular lip and a plastic locking ring removably received within the tubular sleeve.
Accordingly, it is a principal object of the invention to provide a vent stack screen for holding tanks
It is another object of the invention to provide a screen which prevents flying insects from entering a portable toilet through the holding tank.
It is a further object of the invention to provide a vent stack screen which also prevents flying insects and other debris from becoming lodged within vent stacks and preventing proper ventilation of the holding tank of portable toilets.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.